1. Field of the Invention
The present invention relates to an electrical connector assembly, and particularly to a high density electrical connector assembly having a receptacle and a header with identical wafers assembled thereto.
2. Description of Related Art
With the development of communication and computer technology, high density electrical connectors with conductive elements in a matrix arrangement are desired to construct a large number of signal transmitting paths between two electronic devices. Such high density electrical connectors are widely used in internal connecting systems of severs, routers and the like devices requiring high speed data processing and communication.
These connectors generally comprise two mating connector halves, i.e., a header connector connecting with a backplane and a receptacle connector connecting with a daughter card. The backplane and the daughter card are positioned in parallel or perpendicularity to each other. The mating connector halves of one type can be referred to Berg Product Catalog published on January 1998, and the website of Teradyne, Inc, at the following internet address: http://www.teradyne.com/prods/tcs/products/hpi/vhdm/modoconfig.html. Each connector comprises an overmolded carrier made of dielectric material and multiple rows and columns of contacts. Each column of the contacts is provided as a separate module. Multiple modules are installed in the insulating carrier to form a complete connector. Generally, all of the modules are substantially identical. When it is desired to have different types of modules in the connector in order to meet different requirements of signal transmission, a problem is raised that additional tooling and handling are required for the different types of the modules, thereby increasing manufacturing cost.
U.S. Pat. No. 6,152,747, issued to Teradyne, Inc., discloses two mating connector halves 12 and 14 of another type. Each connector half 12 (14) disclosed therein comprises a dielectric housing 20 (200) defining a plurality of slots therein and a plurality of wafer-like modules 42 (230) retained in respective slots. Each wafer-like module includes a dielectric support and a plurality of signal and grounding contacts attached at its opposite sides, respectively. However, the configurations of the wafer-like modules 42 and 230 are different so that they can not be exchanged to be used in the connector half other than they are originally assigned to.
U.S. Pat. No. 6,293,827 discloses an electrical connector providing a wafer assembly 205 having three wafers 210, 212 and 214. Each wafer 210, 212 and 214 has a housing 220A-220C and a plurality of signal contacts 218 held on the housing 220A-220C. Each of the three wafers 210, 212 and 214 has a certain configuration which is different from that of other two wafers. Therefore, three molds must be used to form the wafers. It is costly to manufacture these wafers.
A pair of mating connectors 11 and 18 is disclosed in U.S. Pat. No. 6,267,604. The connector 11 comprises a front housing portion 20 having a front wall 21 with a plurality of parallel apertures 22 extending therethrough, an organizer 30 attached to the front housing portion 20, and a plurality of individual circuit boards or wafers 13 retained between the front housing portion and the organizer. The organizer has a plurality of spaced slots 34 located corresponding to the apertures 22, and a plurality of openings 33 communicating with the slots in a bottom wall thereof. The wafers have mating portions extending through the apertures of the front housing portion for mating with the mating connector 18, and mounting edges received in the slots of the organizer. The mounting edges of the wafers have a plurality of terminals 50 secured thereon by soldering. The terminals extend through respective openings of the organizer for electrically connecting with a circuit substrate. The wafers 13 can not be used in the mating connector 18 to achieve transmitting signal function. Additional contacts 51 must be provided, which results in additional expenditure.
Furthermore, the ""604 patent has the shortcoming that connecting the terminals to the wafers is complicate and time-consuming. Furthermore, once the terminals are connected with the wafers, the terminals cannot be separated from the wafers. If the terminals or wafers are damaged, both of them must be replaced together, thereby increasing the cost of production. In addition, when the wafers are assembled to the organizer, the terminals secured on the wafers need to be received in the respective openings of the organizer for fixing the terminals, thereby increasing the difficulty of assemblage of the wafers.
U.S. Pat. No. 5,980,321 also discloses a backplane assembly which comprises a pin header 114 and a daughter card connector 116. The daughter card connector 116 comprises a wafer 154 having a signal piece 168 and a shield piece 166. Configurations of these pieces 168 and 166 are different with each other; thus, the cost of the connector is high.
Hence, an improved electrical connector assembly is required to overcome the disadvantages of the related art.
Accordingly, an object of the present invention is to provide a high density electrical connector assembly having a plurality of identical wafers assembled in a header and a receptacle of the assembly for reducing the manufacturing cost of the connector assembly.
In order to achieve the objects set forth, an electrical connector assembly comprises a receptacle and a header. The receptacle comprises a first interface connection piece including a plurality of individual first wafers assembled together to define a plurality of slots between adjacent first wafers. Each first wafer includes a dielectric base and a plurality of signal terminals and a grounding member respectively mounted on opposite sides of the dielectric base. The signal contacts and the grounding member have tail portions for connecting to a printed circuit board and contacting portions located at the same side of the dielectric base. A plurality of daughter circuit boards each has a first mating portion and a second mating portion. The first mating portions of the circuit boards are inserted into the slots of the first interface connection piece and mechanically and electrically engage with the contacting portions of the signal contacts and the grounding member. The header for electrically connecting a backplane has a second interface connection piece including a plurality of individual second wafers assembled together to define a plurality of slots between adjacent second wafers. Each second wafer has an identical construction with that of the first wafer of the first interface connection piece. The second mating portions of the circuit boards are inserted into the slots of second interface connection piece and mechanically and electrically engage with signal contacts and grounding member of the second wafers for establishing an electrical connection between the printed circuit board and the backplane.